Page 1 of 1

2004 G3500 Box Truck 274k Service

Posted: Fri May 16, 2025 8:55 am
by rpaoness
Shipping the truck to VT to hopefully stay there a while Sunday night. FIgured I'd get the apparently-almost-annual oil change done at 3100 miles since it looked a touch dark.

I think I added only 1 qt above the "6" we argued about last time (I think 5.7 or 5.8 qts technically?), it was about 1/4-1/3 of range, so probably 1 quart to 1500-2000 miles of consumption is my guess. Doesn't seem bad especially with the towing and loaded hill climbing service it's seen.

Only notable item so far is a weeping transmission output seal. I put a new seal in while I had the trans out. I wonder if I either have a crusty driveshaft OD or a wearing-out tailshaft bearing. Internet seems to say it's a "live" lubricated output bearing, so I'm not sure how much unpressurized slop there should be.

I think I'll run it for now and see if gets worse as long as the trans stays relatively full.

5 quarts of Supertech 5W30 high mileage full synthetic, 1 qt Mobil 1 5W30 high mileage full syn, and an AC Delco PF46E.

Re: 2004 G3500 Box Truck 274k Service

Posted: Fri May 16, 2025 9:54 am
by kevm14
You should be using Valvoline Restore & Protect.

Re: 2004 G3500 Box Truck 274k Service

Posted: Fri May 16, 2025 10:36 am
by rpaoness
Maybe next time (year?). I didn't see it at Walmart, but it looks like it would've been on the shelf at Waterford, just in not in Old Saybrook where I went after dropping off the older two kids at school since I was closer to there.

And that was after I stopped in the Cromwell Walmart last night and they were out of the PF46E filters. Can't seem to win lately.

Looks like $30 for 5 qt. vs. the $18 I paid... I don't know how many more 5W-30 M1 single quarts I still have kicking around.

https://www.walmart.com/ip/Valvoline-Re ... irect=true

If it's really good at cleaning stuff it could clog my oil filter :-)

Re: 2004 G3500 Box Truck 274k Service

Posted: Fri May 16, 2025 10:38 am
by rpaoness
Oil pressure seems responsive somewhat rapidly to RPM changes which is usually a good sign, and I think consumption is down a little. So I'm probably OK. Probably good to keep 2.5k-3k intervals until it looks cleaner.